The Air-Water Interface, when Linked to Capillarity, Influences Water Retention or Evaporation

The drying or water-retention process cannot typically be observed directly in porous materials due to their opacity. In a new study, Prof. David Weitz and colleagues from SEAS and Laboratoire Navier, Université Paris-Est, relied on a simple glass channel which is thin enough to reveal dominant capillary effects—and not just effects linked to waters' fluid nature—that make the water travel along the channel. Using direct microscopic images, they observed the entire air-water interface throughout the capillary, which they then combined with ultra-precise mass measurements and numerical simulations.